A small step towards 'living devices'

Published: 18 May 2007

A new type of biochip encapsulating a slime mould cell has been developed by graduate student Ferran Revilla working with Hywel Morgan and Klaus-Peter Zauner in the School of Electronics and Computer Science (ECS) at the University of Southampton.

The chip provides a controlled environment to keep a plasmodial cell of the true slime mold Physarum polycephalum alive for several days.
One side of the biochip is formed by a microfluidic system which is separated from the slime mold by a membrane through which water and nutrients can be fed to the mold. On the other side of the chip the slime mold is surrounded by 38 electrodes which connect the cell to an analog circuit which monitors the activity of the slime mold cell. The chip is transparent, a feature which allows, in addition to the electrical interfacing, also for optical interfacing with the cell.

Undergraduate student Paul Macey designed and built an electronic interface through which the living slime mold cell can be connected to a USB port on a computer. The interface monitors local mechanical oscillations in the cell by measuring the impedance between combinations of electrodes on the biochip.
The USB interface also provides for stimulating the slime mold with light signals.

Because of the large size of its cells and the ease which with it can be grown the slime mold Physarum polycephalum is a popular model-organism in unconventional computing. It processes information from its environment in a distributed fashion that is not yet well understood. The new chip will provide a way of interacting with the slime mold through a computer and is expected to contribute to the understanding of the slime mold's response to stimuli.

This ongoing collaboration between the Bioelectronics Group and the Science and Engineering of Natural Systems Group explores how microorganisms can be integrated into electronic circuits to create sensors and information processors with components that are alive.